This invention relates to a technology for reading an image drawn on an optical disk.
In optical disks of a CD-R (Compact Disk-Recordable), a CD-RW (Compact Disk Rewritable), a DVD-R (Digital Versatile Disk-Recordable), etc., the descriptions of recorded data cannot be recognized with the naked eye and thus it is difficult to distinguish the optical disks from each other from the appearance of the optical disk unless a label is put or something is printed. Then, an art of drawing a character, a symbol, a pattern, a design, etc., on an optical disk so as to make it possible to easily distinguish the optical disk according to the appearance thereof is proposed. (For example, refer to JP-A-2006-155812, JP-A-2003-16649, etc.)
By the way, a demand for editing an image drawn on an optical disk or adding an image often occurs. In this case, it is preferable to grasp the image already drawn on the optical disk.